Commonly-owned, pending U.S. patent application Ser. No. 08/622,971 filed March 1996, discloses an electrical panel containing an electrically non-conductive basepan for two rows of back-fed circuit breakers. Each of two respective bus bars is disposed on a respective half of a front facing surface of the basepan and connected to an incoming hot feed that is brought into the panel from the electric power utility by one or more incoming hot cables. The two bus bars are separated from each other by a serpentine wall that is present on the basepan between the two bus bars. Each bus bar contains a number of stabs that collectively are arranged in respective rows, and each of which points in a direction toward the deadfront. The serpentine wall has a shape that winds between the stabs of one bus bar and those of the other. A respective back-fed distribution circuit breaker fits onto a respective stab of a bus bar to establish electric connection of the bus bar to the hot side of the circuit breaker. A load wire of each distribution circuit that is served by the electrical panel is attached to the load side of a respective distribution circuit breaker. Neutral bars on the base pan provide for the connection of individual neutral return wires of the respective distribution circuits to a neutral that is brought into the panel from the electric power utility by one or more incoming neutral cables and connected to the neutral bars.
One type of electrical panel has a main circuit breaker through which the incoming hot feed is connected to the distribution circuit breakers. Such a main circuit breaker, like the distribution breakers, is selectively operable to on and off positions. When operated to its on position, it is effective to conduct the hot feed to the distribution circuit breakers, and when operated to its off position, it is effective to shut off the hot feed to the distribution circuit breakers.
In certain electrical panels of this type that have distribution circuit breakers arranged in side-by-side rows as described above, it is believed that there is some benefit in arranging the main circuit breaker in one of the two rows. Such a main circuit breaker may comprise a profile that is essentially like that of the distribution circuit breakers in the same row for fitting to a base pan, the fitting of the distribution circuit breakers to the base pan.
Attachment of such a main circuit breaker to an electrical panel may have to comply with certain applicable standards. For example, one potentially applicable standard provides that before it becomes possible to remove an installed main circuit breaker from a panel, a manual operation must be performed on an attachment that holds the main circuit breaker in place. Such a standard may concern inadvertent, or unintentional, removal of a main circuit breaker from a panel. The manual operation performed on the attachment is generally done with forethought.
It may be desirable to organize and arrange an electrical panel so as to make it more difficult to circumvent potentially applicable standards. For example, a panel that is designed to have two rows of circuit breakers, including a main circuit breaker in one of the rows, may be designed for a maximum number of distribution circuit breakers in each row. In such a design, the row that does not contain the main circuit breaker may have vacant space in the location that is side-by-side with the main circuit breaker. If such a panel is designed to accommodate equal numbers of distribution circuit breakers in each row that add up to the maximum number allowed by a potentially applicable standard, compliance with such a standard may be achieved either by the placement of a prominent warning against attempting to install additional distribution circuit breakers in such vacant space, and/or by mechanically making it more difficult to install extra distribution circuit breakers in the vacant space.
The present invention is directed to a novel attachment for a main circuit breaker that is believed to address concerns such as those just discussed.
A presently preferred embodiment of the invention relates to a main circuit breaker attachment comprising first and second parts, wherein the first part is believed to be a uniquely constructed hold-down for the circuit breaker and the second part is a headed screw for fastening the hold-down in the panel. The hold-down is a non-electrically conductive part, such as a suitably molded plastic. The hold-down engages the main circuit breaker, and a shank of the headed screw passes through a through-hole in the hold-down to thread into a hole in the base pan. The screw is tightened against the hold-down to hold it, and in turn the main circuit breaker, in place. In such an installed condition, the main circuit breaker cannot be removed at least easily from the panel unless the screw is first sufficiently loosened, and perhaps even removed from the hold-down, to allow movement of the hold-down to a position that enables the main circuit breaker to be removed. Because unfastening of the attachment screw may involve the use of a hand tool such as a screwdriver, the hold-down includes certain features that are intended to minimize or at least reduce the risk that the tool might contact parts other than the attachment screw and the hold-down during the process of unfastening the attachment screw. The hold-down further includes a finger-grippable tab that is designed both to facilitate installation and removal, and to provide an obstruction to any attempted, potentially non-compliant, installation of one or more extra distribution circuit breakers in vacant space along side the main circuit breaker that is being held in place by the hold-down. The tab may be provided with further useful features, such as texturing or ribbing to facilitate gripping, and informational and/or warning indicia. The hold-down may also be distinctively colored as a potential aid in directing a person's attention to it so that the presence of a main circuit breaker in a panel may be better recognized.
One object of the invention is to provide an electric distribution panel through which incoming electric power is distributed through circuit breakers to individual distribution circuits, the panel comprising: a main circuit breaker through which incoming electric power passes; a number of individual distribution circuit breakers; first and second bus bars for delivering incoming electric power from the main circuit breaker to the individual distribution circuit breakers; an attachment for attaching the main circuit breaker to the panel that requires performance of a manual operation before the main circuit breaker can be detached from the panel; the attachment comprising a first part and a second part; the first part having an association with the main circuit breaker, when the first part is disposed in an attached position, to prevent the main circuit breaker from being detached from the panel; the second part having an association with the first part, when the first part is in attached position and when the second part is in an attaching position, that keeps the first part in attached position; and the second part being operable by a manual operation from attaching position to a non-attaching position to allow the first part to move to a non-attached position that ceases to at least better prevent the main circuit breaker from being detached from the panel.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the main circuit breaker comprises two side-by-side conjoined circuit breakers, and the first part comprises a body with which the second part has association and a projection projecting from the body to fit between the side-by-side conjoined circuit breakers that at least better prevent them from being detached from the panel.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the body comprises a through-hole and the second part comprises a fastener that acts via the through-hole to hold the first part in the panel.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the fastener comprises a screw having a head that bears against the body and a threaded shank that extends from the head through the through-hole.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the body comprises a frontally facing surface against which the screw head bears and a wall extending frontally from the frontally facing surface and circumferentially bounding at least a portion of the screw head.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the body comprises a walled well having a frontal opening disposed adjacent the through-hole.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the wall extending frontally from the frontally facing surface and circumferentially bounding at least a portion of the screw head fully circumferentially bounds both the screw head and the frontal opening of the well.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the projection projects laterally from a first side of the body, and the body includes a further projection projecting from a second side of the body opposite the first side.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the further projection comprises a tab occupying a plane that is skewed to the length of the through-hole.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the further projection comprises a tab that has a size sufficient for gripping between a person's thumb and forefinger.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the first part comprises a body having a circuit-breaker-engaging projection at a first side of the body engaging the main circuit breaker and a tab projecting from a second side of the body.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the first and second sides of the body are disposed opposite each other and the tab extends at an angle frontally of the body.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the body comprises a through-hole and the second part comprises a fastener that acts via the through-hole to hold the first part in the panel.
Still another object of the invention is to provide a hold-down for use in attaching a circuit breaker to an electrical panel comprising a non-electrically conductive body, a circuit-breaker-engaging projection at a first side of the body for engaging a circuit breaker and a gripping tab projecting from a second side of the body.
Still another object of the invention is to provide a hold-down as set forth above wherein the first and second sides of the body are disposed opposite each other and the gripping tab extends at an angle frontally of the body.
Still another object of the invention is to provide a hold-down as set forth above wherein the body comprises a through-hole having an entrance at a frontal surface of the body that is disposed between the first and second sides.
The foregoing, along with further features, advantages, and benefits of the invention, will be seen in the ensuing description and claims, which are accompanied by drawings. The description and drawings disclose a presently preferred embodiment of the invention according to the best mode contemplated at this time for carrying out the invention.